A wide variety of semiconductor devices are currently available.
Semiconductor devices are typically composed of materials that have had their electrical characteristics altered by the addition of impurities. If an electrical signal is applied to a semiconductor device, it will operate predictably according to the electrical properties of the materials included in the semiconductor device.
Semiconductor devices can be classified as diodes, Bipolar Junction Transistors (BJT), or Field Effect Transistors (FET), according to the semiconductor material components, the layer structure of the semiconductor material, and the operational characteristics.